Fix metadata types

[fengelniederhammer]

PR Checklist

• [ ] All necessary documentation has been adapted.
• The implemented feature is covered by an appropriate test.

[TobiasKampmann]

LGTM

[corneliusroemer]

How did this manifest pre-PR? Was anything broken? What's possible now that wasn't before?

[fengelniederhammer]

Ah yes, I wanted to add a screenshot, but forgot. This happens on the review page:

(The component probably crashes, thus no metadata is shown)

On the edit page, there is a validation error from zod that the types don't match:

I.e. we need to take care of null values there.

[fengelniederhammer]

We should probably rework this at some point to show less frightening errors to the users:

• Either we know the error is fine and show it in a nice box
• or we show something like "Oops, something went wrong, please contact the admin with this log trace id"

[corneliusroemer]

Thanks so much @fengelniederhammer - I had no clue what this PR was fixing and your summary makes it very easy to understand!

[corneliusroemer]

Do you want to test in a preview? 😜 I didn't realize this isn't actually merging into main, so ignore - it can be tested in the main PR

[fengelniederhammer]

I found it while reviewing the PR of the base branch of this - so I didn't want to clutter that. I'll wait until that is merged and merge this to main then.